Commit 4c9451ed authored by Johannes Berg's avatar Johannes Berg
Browse files

mac80211: factor out 802.11 header building code 



Factor out the 802.11 header building code from the xmit function
to be able to use it separately in a later commit.

While at it, fix up some documentation.

Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
Signed-off-by: default avatarArik Nemtsov <arik@wizery.com>
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent 73c4e195

net/mac80211/tx.c

+92 −52
Original line number Diff line number Diff line
@@ -1784,24 +1784,26 @@ static void ieee80211_tx_latency_start_msrmnt(struct ieee80211_local *local, 
}



/**

 * __ieee80211_subif_start_xmit - netif start_xmit function for Ethernet-type

 * subinterfaces (wlan#, WDS, and VLAN interfaces)

 * @skb: packet to be sent

 * @dev: incoming interface

 * ieee80211_build_hdr - build 802.11 header in the given frame

 * @sdata: virtual interface to build the header for

 * @skb: the skb to build the header in

 * @info_flags: skb flags to set

 *

 * On failure skb will be freed.

 * This function takes the skb with 802.3 header and reformats the header to

 * the appropriate IEEE 802.11 header based on which interface the packet is

 * being transmitted on.

 *

 * This function takes in an Ethernet header and encapsulates it with suitable

 * IEEE 802.11 header based on which interface the packet is coming in. The

 * encapsulated packet will then be passed to master interface, wlan#.11, for

 * transmission (through low-level driver).

 * Note that this function also takes care of the TX status request and

 * potential unsharing of the SKB - this needs to be interleaved with the

 * header building.

 *

 * The function requires the read-side RCU lock held

 *

 * Returns: the (possibly reallocated) skb or an ERR_PTR() code

 */

void __ieee80211_subif_start_xmit(struct sk_buff *skb,

				  struct net_device *dev,

				  u32 info_flags)

static struct sk_buff *ieee80211_build_hdr(struct ieee80211_sub_if_data *sdata,

					   struct sk_buff *skb, u32 info_flags)

{

	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);

	struct ieee80211_local *local = sdata->local;

	struct ieee80211_tx_info *info;

	int head_need;
@@ -1821,20 +1823,13 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb, 
	struct ieee80211_chanctx_conf *chanctx_conf;

	struct ieee80211_sub_if_data *ap_sdata;

	enum ieee80211_band band;



	if (unlikely(skb->len < ETH_HLEN))

		goto fail;

	int ret;



	/* convert Ethernet header to proper 802.11 header (based on

	 * operation mode) */

	ethertype = (skb->data[12] << 8) | skb->data[13];

	fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);



	rcu_read_lock();



	/* Measure frame arrival for Tx latency statistics calculation */

	ieee80211_tx_latency_start_msrmnt(local, skb);



	switch (sdata->vif.type) {

	case NL80211_IFTYPE_AP_VLAN:

		sta = rcu_dereference(sdata->u.vlan.sta);
@@ -1852,8 +1847,10 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb, 
		ap_sdata = container_of(sdata->bss, struct ieee80211_sub_if_data,

					u.ap);

		chanctx_conf = rcu_dereference(ap_sdata->vif.chanctx_conf);

		if (!chanctx_conf)

			goto fail_rcu;

		if (!chanctx_conf) {

			ret = -ENOTCONN;

			goto free;

		}

		band = chanctx_conf->def.chan->band;

		if (sta)

			break;
@@ -1861,8 +1858,10 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb, 
	case NL80211_IFTYPE_AP:

		if (sdata->vif.type == NL80211_IFTYPE_AP)

			chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);

		if (!chanctx_conf)

			goto fail_rcu;

		if (!chanctx_conf) {

			ret = -ENOTCONN;

			goto free;

		}

		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);

		/* DA BSSID SA */

		memcpy(hdr.addr1, skb->data, ETH_ALEN);
@@ -1949,8 +1948,10 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb, 


		}

		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);

		if (!chanctx_conf)

			goto fail_rcu;

		if (!chanctx_conf) {

			ret = -ENOTCONN;

			goto free;

		}

		band = chanctx_conf->def.chan->band;

		break;

#endif
@@ -1980,8 +1981,10 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb, 
		 * of a link teardown after a TDLS sta is removed due to being

		 * unreachable.

		 */

		if (tdls_peer && !tdls_auth && !tdls_setup_frame)

			goto fail_rcu;

		if (tdls_peer && !tdls_auth && !tdls_setup_frame) {

			ret = -EINVAL;

			goto free;

		}



		/* send direct packets to authorized TDLS peers */

		if (tdls_peer && tdls_auth) {
@@ -2009,8 +2012,10 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb, 
			hdrlen = 24;

		}

		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);

		if (!chanctx_conf)

			goto fail_rcu;

		if (!chanctx_conf) {

			ret = -ENOTCONN;

			goto free;

		}

		band = chanctx_conf->def.chan->band;

		break;

	case NL80211_IFTYPE_OCB:
@@ -2020,8 +2025,10 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb, 
		eth_broadcast_addr(hdr.addr3);

		hdrlen = 24;

		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);

		if (!chanctx_conf)

			goto fail_rcu;

		if (!chanctx_conf) {

			ret = -ENOTCONN;

			goto free;

		}

		band = chanctx_conf->def.chan->band;

		break;

	case NL80211_IFTYPE_ADHOC:
@@ -2031,12 +2038,15 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb, 
		memcpy(hdr.addr3, sdata->u.ibss.bssid, ETH_ALEN);

		hdrlen = 24;

		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);

		if (!chanctx_conf)

			goto fail_rcu;

		if (!chanctx_conf) {

			ret = -ENOTCONN;

			goto free;

		}

		band = chanctx_conf->def.chan->band;

		break;

	default:

		goto fail_rcu;

		ret = -EINVAL;

		goto free;

	}



	/*
@@ -2074,12 +2084,13 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb, 
		      !ether_addr_equal(sdata->vif.addr, skb->data + ETH_ALEN)))) {

#ifdef CONFIG_MAC80211_VERBOSE_DEBUG

		net_info_ratelimited("%s: dropped frame to %pM (unauthorized port)\n",

				    dev->name, hdr.addr1);

				    sdata->name, hdr.addr1);

#endif



		I802_DEBUG_INC(local->tx_handlers_drop_unauth_port);



		goto fail_rcu;

		ret = -EPERM;

		goto free;

	}



	if (unlikely(!multicast && skb->sk &&
@@ -2116,8 +2127,10 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb, 
		skb = skb_clone(skb, GFP_ATOMIC);

		kfree_skb(tmp_skb);



		if (!skb)

			goto fail_rcu;

		if (!skb) {

			ret = -ENOMEM;

			goto free;

		}

	}



	hdr.frame_control = fc;
@@ -2166,7 +2179,7 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb, 
		if (ieee80211_skb_resize(sdata, skb, head_need, true)) {

			ieee80211_free_txskb(&local->hw, skb);

			skb = NULL;

			goto fail_rcu;

			return ERR_PTR(-ENOMEM);

		}

	}
@@ -2200,9 +2213,6 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb, 
	nh_pos += hdrlen;

	h_pos += hdrlen;



	dev->stats.tx_packets++;

	dev->stats.tx_bytes += skb->len;



	/* Update skb pointers to various headers since this modified frame

	 * is going to go through Linux networking code that may potentially

	 * need things like pointer to IP header. */
@@ -2213,23 +2223,53 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb, 
	info = IEEE80211_SKB_CB(skb);

	memset(info, 0, sizeof(*info));



	dev->trans_start = jiffies;



	info->flags = info_flags;

	info->ack_frame_id = info_id;

	info->band = band;



	ieee80211_xmit(sdata, skb);

	rcu_read_unlock();

	return skb;

 free:

	kfree_skb(skb);

	return ERR_PTR(ret);

}



void __ieee80211_subif_start_xmit(struct sk_buff *skb,

				  struct net_device *dev,

				  u32 info_flags)

{

	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);

	struct ieee80211_local *local = sdata->local;



	if (unlikely(skb->len < ETH_HLEN)) {

		kfree_skb(skb);

		return;

	}



 fail_rcu:

	rcu_read_lock();



	/* Measure frame arrival for Tx latency statistics calculation */

	ieee80211_tx_latency_start_msrmnt(local, skb);



	skb = ieee80211_build_hdr(sdata, skb, info_flags);

	if (IS_ERR(skb))

		goto out;



	dev->stats.tx_packets++;

	dev->stats.tx_bytes += skb->len;

	dev->trans_start = jiffies;



	ieee80211_xmit(sdata, skb);

 out:

	rcu_read_unlock();

 fail:

	dev_kfree_skb(skb);

}



/**

 * ieee80211_subif_start_xmit - netif start_xmit function for 802.3 vifs

 * @skb: packet to be sent

 * @dev: incoming interface

 *

 * On failure skb will be freed.

 */

netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,

				       struct net_device *dev)

{

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